CVD AKA China Video Disk...
09/10/98 South China Morning Post Page 4
(c) Copyright 1998 South China Morning Post Publishers. All Rights Reserved.
The original Video CD formats, all the way up to Version 2.0, provide average to above-average image and sound quality, depending on the source. However, VCD quality does not degrade over multiple showings, unlike videotape, but remains readable by all formats, including existing VCD and DVD players and next-generation VCD players such as Super Video CD (SVCD), China Video Disk (CVD), and HiQ VCD.
Since CDs are cheap to make, manufacturing plants have sprung up in the mainland which will be able to make CDs under the new VCD formats with minimal, if any, changes.
DVDs physically are similar to CDs, but store about eight times the amount of data of a CD. Picture resolution is about double, and cinema-quality audio is enabled by Dolby Digital decoding and 5.1 channel sound.
However, DVDs cannot be read by VCD or CD players, although the reverse is true - DVD players can read the lower-quality VCDs and CDs.
DVDs also initially are more expensive to make than CDs because they require different machinery, additional training, and purchase of technology licences.
The three VCD formats all propose to raise video quality to a level in between that of existing Video CDs and DVDs. They would achieve this by using a more efficient way to store and compress data.
In this case, it would be MPEG-2 compression, which is more efficient than the MPEG-1 compression used with the original VCD formats.
However, the formats clash on small technical details, such as how many lines are displayed on screen.
Also, in order to remain compatible with existing CD-manufacturing equipment, these VCD formats sacrifice certain DVD features, such as Dolby Digital sound, letter-boxed formats, and differently rated movie versions.
C - Cube claims that features such as 5.1 channel sound and language support will be implemented by CVD.
At the moment, the three proposed VCD formats appear to be incompatible with each other, and with existing DVD players.
Reports say that both C - Cube and the HiQ VCD consortium are attempting to persuade the MII to adopt their respective specifications as the choice for SVCD.
The C - Cube representative said its CVD products should be able to play SVCD discs when the standard was finalised later this year, and added that the company's DVD products also would be compatible with its CVD-spec disks.
Yang-Wahn Hew
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